Bachelor of Pharmacy invloves 70% of organic chemistry in the entire syllabus. So if you are not so good at Organic Chemistry the path of this 4 years would be difficult. But you can start your preparing for Organic Chemistry from now if you wish to join Bachelor of Pharmacy. Organic Chemistry requires understanding of reactors, reactants. By writing the equations again and again you can get a grip over them. If possible make a chart of reactors, reactant, catalysts etc. Organic Chemistry requires daily practice. And this should be an integral part of your preparation. NCERT class 11 and 12 are the best for building core organic knowledge. Another best book that can help you in Organic Chemistry is MS Chauhan.